As they reported in PLoS One, the researchers tagged DNA expressing enhanced green fluorescent protein (EGFP) to two nanoparticle formulations and injected each of them into two eye compartments. Using quantitative RT-PCR and fluorescence microscopy to detect EGFP expression, the researchers noted good expression of the transgene compared to the injection of "naked" DNA.

They also noted a strong correlation between injection site—intravitreal versus subretinal—and tissue-specific EGFP expression, offering the possibility of precisely targeted gene therapy. Furthermore, using electroretinography to test retinal activity, the researchers determined that the nanoparticles had no toxic impact on eye tissues.